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Item type:Publication, Access status: without files , Implantable medical systems for the invasive monitoring of pressure and temperaturePublicationtype: Doctoral Thesis59 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , A 1.9 nW Timer and Clock Generation Unit for Low Data-Rate Implantable Medical DevicesThis work presents a thyristor-based low power timer for wake up control of implantable monitoring devices, as well as a clock generation unit based on said approach. By using CMOS thyristors as delay elements in a ring oscillator, major drawbacks of conventional ring oscillators, such as a high stage count of inverters and capacitors with large currents flowing t o g round d uring s witching, c an b e o vercome. T his is particularly relevant for low frequency generation where these issues become even more critical in terms of power and area. Thyristors generate larger delays per stage while presenting a faster transition when switching between states, when compared to a typical CMOS inverter, an thus demand a smaller dynamic power. Timer, clock gating control and clock generation units were combined, implemented, and fabricated in 350 nm CMOS technology. The timer is able to wake up the clocking system (and hence a digital control unit) every 32.45 s with a power budget of less than 2 nW, while the clock generation unit produces a signal of 8.2 kHz.Publicationtype: Conference Paper93 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , A 16-bit Pressure Sensing Interface Integrating a 460 fJ/conv Incremental Sigma Delta ADC for Medical DevicesThis work presents an incremental 2nd-order sigma delta using a single operational transconductance amplifier. This design provides a good trade-off between time conversion, high bit resolution, power consumption and area utilization for a pressure sensing reading interface. The modulator, designed in 180 nm CMOS technology, has been optimized for low area utilization, occupying only 0.058 mm2. Post-layout simulations were performed showing a resolution of 150 μV while consuming 120 μW and 460 fJ/conv. The system has a resolution of 16 bits, a bandwidth of 2 kHz, an oversampling ratio of 512 and a sampling frequency of 2 MHz.Publicationtype: Conference Paper98 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Additively manufactured anatomical heart model for performance evaluation of aortic valve implants(Infinite Science Publishing, 2020); ; ; It is suspected that the minimal invasive implantation of aortic valves (TAVI procedure) causes damage to the implant that affects its performance. Medical simulators can be used to investigate this suspicion systematically, repeatedly and under constant conditions. This paper describes the development of a heart model that extends the existing HANNES simulator for aortic valve performance evaluation. The advantages of additive manufacturing (AM) are used to provide an anatomically realistic replication of the relevant anatomical sections of the heart and the aortic root.Publicationtype: Journal Article278 246 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , A Pressure sensor with 0.30 mmhg resolution incorporating a 4.19 pj/conv thyristor-based capacitance-To-Time converter for intra-corporeal Pressure Monitoring ApplicationsThis work presents a Capacitance-To-Digital Converter for in-vivo pressure monitoring in clinical scenarios. The developed system combines a Capacitance-To-Time Converter (CTC) and a Time-To-Digital Converter (TDC), of which the CTC presents a novel architecture based on CMOS Thyristor elements with a power consumption of only 2.99 μW. The interface was implemented in a 350 nm CMOS technology and tested in combination with a commercially available capacitive pressure transducer. The Capacitance-To-Time Converter unit achieves an average pressure resolution of 0.30 mmHg while consuming 4.19 pJ/conv.Publicationtype: Conference Paper124 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , 3D-printing technology as a tool for medical implantable electronic devices(Infinite Science Publishing, 2019); ; ; Medical implantable electronic devices (IMD) are of great use to research and in the treatment of various health conditions. 3D printing technology is proving to revolutionize multiple industries, including IMDs, by allowing rapid research, development and production. This paper presents how 3D printing technology was utilized during the modeling, prototyping and fabrication process of the first version of an implantable device intended for interstitial pressure monitoring.Publicationtype: Journal Article118 142 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Ultra-low-power self-biased 1 na current reference circuit for medical monitoring devices in 350 nm and 180 nm CMOS technology(VDE Verlag GmbH, 2018-09); ; ; This paper describes a 1 nA current reference designed in 180 nm and 350 nm CMOS technologies. The proposed design is an enhancement of Oguey’s reference circuit. This improved design provides a temperature stable current of 1 nA within the temperature range from −45◦C to 85◦C, with a simulated temperature coefficient (TC) of 388 ppm/◦C and 281 ppm/◦C in 180 nm and 350 nm technologies, respectively. The operating voltage for the proposed circuit ranges from 1.4 to 2.1 V in 180 nm design, with a power consumption of 126 nW@1.8 V. In 350 nm design the operating voltage is from 2.7 to 3.3 V, with a power consumption of 2.1 µW@3.3 V. Measurements of the proposed design fabricated in 350 nm technology are explained in detail in section 3.2.Publicationtype: Conference Paper84 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Super-capacitors for implantable medical devices with wireless power transmissionPatients using implantable devices with wireless power transmission (such as inductive telemetry) as the energy source are required to carry external hardware and antennas on their body continuously during the monitoring period. This discomfort can be reduced by integrating tiny super-capacitors as an energy source for the device. The external wireless telemetry unit used to activate and interrogate the implantable device charges the super capacitors integrated on it. When the wireless telemetry unit is removed, the super capacitor powers the implantable device. This paper shows the benefits of integrating super capacitors onto an existing pressure sensing medical implant that utilises an inductive telemetry link. Test results show that the implant can be powered for a full day using an 88 mF super capacitor. This super capacitor can be fully charged using the inductive telemetry link at a wireless distance of 20 cm in 81 seconds.Publicationtype: Conference Paper460 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Integration of Double Barrier Memristor Die with Neuron ASIC for Neuromorphic Hardware Learning(IEEE, 2018-04-26); ; ; ; This paper details the design of an integrate fire (I F) neuron ASIC and its integration with a double barrier memristor device. The memristor has a non-volatile analog memory characteristic which changes with time and voltage. The neuron ASIC is designed to interact with the memristor by integrating its current and firing when a certain threshold is reached. The resulting spikes increase the memristor's conductance and consequently the firing rate of neuron increases. Together, the ASIC and the memristor mimics neuromorphic learning on hardware. The ASIC has been fabricated in AMS 350nm process.Publicationtype: Conference Paper186 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Integrated circuit with memristor emulator array and neuron circuits for biologically inspired neuromorphic pattern recognition(World Scientific Publishing (WSPC), 2017-04-27); ; ; ; This paper details an application-specific integrated circuit (ASIC) with an array of switched-resistor-based memristors (resistor with memory) and integrate & fire (I & F) neuron circuits for the development of memristor-based pattern recognition. Since real memristors are not commercially available, a compact memristor emulator is needed for device study. The designed ASIC has five memristor emulators with one having a conductance range from 4.88ns to 4.99μs (200kOhm) to 204.8MOhm)) and other four having conductance ranging from 195ns to 190μs (5.2kOhm) to 5.12MOhm)). Signal processing has been planned to be off-chip to get the freedom of programmability of a wide range of memristive behavior. This paper introduces the memristor emulator and the realization of synapse functionalities used in neuromorphic circuits such as long term potentiation (LTP), Long Term depression (LTD) and synaptic plasticity. The ASIC has two I & F neuron circuits which are intended to be used in conjunction with memristors in a multiple chip network for pattern recognition. This paper explains the memristor emulator, I & F neuron circuit and a respective neuromorphic system for pattern recognition simulated in LTspice. The ASIC has been fabricated in AMS 350nm process.Publicationtype: Journal ArticleScopus© Citations 11 372 470